Good samples or photographs will make it much easier to identify a problem. Some tips for bringing in live samples to a NC Cooperative Extension Office:
Plant Samples
1. Gather samples from the healthy part of the plant as well as the damaged or diseased sections. This will help identify what the “normal” growth looks like next to the problem. If possible, it is helpful to gather samples from older growth and new growth. If multiple plants of the same type are present, taking samples of plants in various stages of the problem will be helpful.
2. Take a large enough sample that leaves are still attached to stems. Pulling a few individual leaves from the plant will not provide as much information as intact stems.
3. Look for evidence of cankers along the stem and gather a sample.
4. For roots, remove sections of healthy, as well as diseased root tissue, along with some of the surrounding soil.
5. Bring samples in immediately. If they do need to be stored, put them in a dry plastic bag in the refrigerator or cooler.
Insect Samples
1. Collect any insects present; looking for adult as well as immature forms.
2. Be sure to collect any samples of the damage the insects are believed to have caused.
3. Place insects in a tightly lidded glass jar and fill with rubbing alcohol or put in the freezer for several hours. If it is not possible to bring in a sample, quality photographs can be submitted.
Quality Photographs
1. To help identify a plant, document the leaf pattern (alternate, opposite), leaf margins, bark, and flowers or fruits if present.
2. To identify an insect, look for both mature and immature forms. Close-ups of legs and antennae can be particularly helpful. Images of damage they have done, frass or casings can also help with identification.
3. To diagnose a problem, be sure to capture healthy parts of the plant, as well as parts that are damaged. Include an image of the entire landscape, the entire plant, as well as close-up images of the problem area, and an image that shows both the problem area and healthy tissue if possible. If symptoms are occurring on leaves, take pictures of both the top and the underside of a leaf.
4. Take multiple shots with different camera settings to help ensure the best shot.
5. Use a scale object like a coin or a thumb.
6. Use a fast shutter speed for moving insects and animals to lessen blurring.
7. Use macro settings to ensure an in-focus image when taking close-ups.
8. For birds, butterflies, or other fast moving subjects, set the camera up on a tripod, turn it on, focus and wait for a good shot.
For more detailed information about gathering samples for submittal, please review the steps on the North Carolina Plant Disease and Insect Clinic’s website: How to Gather Samples
This information was taken from the Extension Gardener Handbook, Chapter 7 (Diagnostics), VII (Submitting Samples).